Integrated Assessment of Sulfur Emissions from a Coastal Gas Processing Facility in Libya

Abstract

Sulfur emissions from natural gas processing facilities remain an important environmental concern, particularly in regions with limited monitoring data. This study presents an integrated assessment of hydrogen sulfide (H₂S) and sulfur dioxide (SO₂) emissions from the Mellitah Oil and Gas Complex, Libya, using ground-based measurements and Sentinel-5P/TROPOMI satellite observations. Field monitoring along a 900 m downwind transect showed substantial concentration decreases with distance, with H₂S declining from 0.030 to 0.008 ppm and SO₂ from 0.050 to 0.014 ppm. Exponential decay models indicated slightly greater persistence of SO₂ than H₂S. Diurnal analysis revealed higher concentrations during morning and evening periods due to more stable atmospheric conditions. Satellite observations identified persistent SO₂ enhancements over the facility throughout 2019, with an annual mean vertical column density of 2.212 × 10⁻⁴ mol m⁻² and a pronounced peak in December. The results confirm that the Mellitah facility is a significant local and regional source of sulfur emissions. The study demonstrates the effectiveness of combining field measurements with satellite observations for air-quality assessment in data-sparse regions and provides a practical framework for environmental monitoring of industrial emissions.